1. Field of the Invention
The present invention relates to a sensor device, sensing method, biological substance sensor device, biological substance sensing method, secretion sensor device, secretion sensing method, emotion sensor device and emotion sensing method that are especially suitable for application to measurement of emotion by detecting changes in secretory amount of a secretion product caused by human mental movements.
2. Description of the Related Art
The modern information society is rapidly establishing its ground concerning transmission of information by communication and holding of information by storage. The most important techniques requested upon the ground are considered to be directed to two issues, namely, how to ingest which effective kind of information, and how to transfer the information to people. Sensors are one of techniques for the former issue. The sensor technology, however, is also considered a basic technique necessary for effective transfer that is the latter issue.
Many sensors have been developed heretofore (Kiyoshi Takahashi et al.: “Sensor no Jiten (Dictionary of Sensors)”, Asakura Shoten, 1991; Kinji Koshitani: “Zukai de Wakaru Sensor no Hanashi (Illustrated Story of Sensors)”, Nippon Jitsugyo Publishing Co., Ltd., 1995). These sensors can be roughly divided to three categories, namely, physical sensors, chemical sensors and biosensors in terms of their measurement principles. A wide variety of sensors have been known, such as photo sensors and temperature sensors as physical sensors, ion sensors and gas sensors as chemical sensors, and DNA sensors and immune sensors as biosensors. They also have a broad range of applications, but most of them have the disadvantage that each has a single function and can measure only one piece of information each time.
As a technique to cope with the above-indicated disadvantage, the concept of sensor fusion is now under researches (Hiroo Yamazaki and Masatoshi Ishikawa: “Sensor Fusion: Jissekai no Noudouteki Rikai to Chiteki Kousei (Sensor Fusion: Active Understanding of Its Real World and Intellectual Reconstruction)”, Corona Publishing Co., Ltd., 1992). Sensor fusion pertains to simultaneously ingesting a variety of sensor information and appropriately processing them to extract information that cannot be obtained with a single sensor.
Also known are sensors of a type configured to measure information of a system variable in nature by combination of target physical objects (N. Hoshimiya: “Seitai Jouhou Keisoku (Biological information Measurement)”, Morikita Shuppan Co., Ltd., 1997). There are some different types of sensor linkage sites depending upon natures of targets. To deal with proteins as the target, the use of antibody/antigen reaction and the use of metal nanoparticles with appropriate linkers bonded have been reported (Christof M. Niemeyer: “Nanoparticles, Proteins, and Nucleic Acids: Biotechnology Meets Materials Science”, Angew. Chem. Int. Ed. 2001, 40, 4128-4158). To deal with DNA chains as the targets, there is a proposal of winding DNA chains having base sequence sites complementary to the targets on metal nanoparticles (Christof M. Niemeyer: “Nanoparticles, Proteins, and Nucleic Acids: Biotechnology Meets Materials Science”, Angew. Chem. Int. Ed. 2001, 40, 4128-4158). To deal with DNA chains as the targets, there is another proposal of fixing one end of complementary DNA to a substrate and fixing a metal nanoparticle to the other end (A. Yamaguchi, S. Juodkazis, S. Matsuo, and H. Misawa; “Enhancement of surface plasmon resonance sensing of DNA hybridization using colloidal Au attached probe DNA, Chem. Lett.”, p. 190 (2002)).
It is also known that stress has a certain relation to the central nerve system, automatic nerve system, endocrine system and immune system (Hiroshi Miyata as editor: “Shin Seiri Shinrigaku 1 (New Physiological Psychology 1)”, Kitaoji Shobo, 1998, pp 281-282).
Further, there are proposed methods of measuring stress or emotion from a secretion product (Japanese Patent Laid-open JP-2002-188996-A2; Japanese Patent Laid-open JP-2002-168860-A; Japanese Patent Laid-open JP-H10-239312-A).
The sensor fusion, however, is a technique directed mainly to enabling human intellectual recognition and formation of a concept, and it is not a technique for measuring different pieces of information from various aspects of a single target. Therefore, for applications other than high-order functions such as intellectual procedures, heavy processing load is considered to become a problem.